A new poll has another batch of bad news for Hillary Clinton

She received her worst favorability rating ever. She's lost ground on Republicans' three strongest candidates. And she's about as honest and trustworthy as Donald Trump.

Those are some of the troubling numbers for former Secretary of State Hillary Clinton in a new poll released Thursday by Quinnipiac University.

The poll still shows her with a commanding lead in the Democratic race, as she leads with 55% of the Democratic vote nationwide.

US Sen. Bernie Sanders (I-Vermont), who is running as a Democrat, grabs 17% of the vote. Vice President Joe Biden, who has not yet said whether he will run, gets 13% support from Democratic primary voters.

From there, though, the numbers show some complications for the Democratic front-runner. For one, Biden is running about as well against top Republicans in hypothetical general-election matchups. She has lost significant ground against those foes since Quinnipiac's poll from May.

Here's a quick breakdown:

• Clinton trails former Florida Gov. Jeb Bush (R) 42-41. She led Bush by 10 points in May. Biden, on the other hand, leads Bush by 1 point.
• Clinton leads Wisconsin Gov. Scott Walker (R) 44-43. She led Walker by 8 points in May. Biden is tied with Walker.

Clinton does, however, lead real-estate magnate Donald Trump by 12 points in a theoretical general-election matchup.

"The good news for Secretary Hillary Clinton is that she is over 50% among Democrats and has a double-digit lead over Trump," said Tim Malloy, the assistant director of the Quinnipiac University Poll.

"The not-so-good news is that she is locked in too-close to call races with Wisconsin Gov. Scott Walker and former Florida Gov. Jeb Bush. And Vice President Joseph Biden runs just as well as her against the top Republicans."

Clinton also recorded her worst favorability score ever in the Quinnipiac survey. Just 40% of voters view her favorably, compared with 51% who see her in an unfavorable light. Biden gets a 49-39 split on favorability, his best score in seven years. And Bush (43-41) and Walker (36-27) are both in positive territory.

Finally, continuing a trend seen in key swing-state polls last week, most voters do not view Clinton as "honest and trustworthy." By a 57-37 margin, poll respondents said Clinton is not honest and trustworthy. And 52% said she "doesn't care about their needs or problems."

The "honest and trustworthy" numbers put her almost on par with Trump: Voters say by a 58-33 margin that he is not honest and trustworthy.

"Republicans say Trump is honest and Democrats say Clinton is honest, but among all voters, both candidates come up short," Malloy said. "How can you become a general election front-runner if most voters don't trust you?"